| Pages:
1
..
15
16
17
18 |
Bert
Super Administrator
Posts: 2821
Registered: 12-3-2004
Member Is Offline
Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
|
|
Quote: Originally posted by Hey Buddy  | I've been doing sabanejeff-oxidation derived lead azide (dextrin and cmc). I saw this demonstration set up on Astral Chemistry's video channel. This
photo is the first arrangement used. I copied his set up. Sidearm test tube as reaction vessel. HN3 diluted with N2 and NO2 is generated and fed into
a broke off pipette tip through a two hole stopper into lead acetate/cmc/dextrin aqueous solution. The other hole in the stopper has a short section
of pipette connected to a vinyl output hose feeding into a water trap. Hydrazine sulfate and 50% concentration nitric acid are loaded into the
reaction chamber, a gentle heat is applied to the reaction tube, around 30 sec to a min of heating by an electric heat gun initiates the reaction
smoothly. Generating a movement of the reaction mixture and a fizzing followed by bubbling then intense bubbling then tapering off. Mixed HN3 gas is
fed into the receiver chamber loaded with your solution of choice, inorganic hydroxides, acetates and nitrates are the usual solutions.
I have not attempted this with organic substrates. I have been trying this set up using OTC drain cleaner/ AN in situ nitric acid salt mix, instead of
the usual diluted HNO3. It generates HN3 almost as smoothly as using HNO3.
I have had some lessons learned using this set up. Obviously, HN3 is the greatest danger presented by any method using hydrazoic acid, its very
poisonous and explosive when concentrated. This method is advantageous in that its risk of detonation is minimized by small amounts of gas produced at
a time as the reaction proceeds and the gas then neutralized at end point use creating azide directly. The gas is also diluted by the nitric acid
presence which is definitely feeding NO and NO2 and maybe some N2 into the stream.
The gas pressure can become intense depending on the vessel and mass of reactants. Astral recommended 1.5 g N2H6SO4 for 4 cc of 50% HNO3. That ratio
works smoothly. In modifying the procedure to use NO3 salt, I tried at first mixing hydrazine salt with nitrate salt in the reactor and adding H2SO4.
This results in quite an immediate reaction. Ive also blown off the stopper from excess gas pressure from too vigorous of a gas generation, this
should be avoided because it off vents hydrazoic acid into the ambient environmentif you are not using a hood. A better method is to first react the
H2SO4 with nitrate salt for around 15 minutes prior to loading it into the reactor with the hydrazine inside. This method has no immediate reaction
and a reaction doesnt begin until the reactor is heated to around ~100 C.
I have also had issues with bubbling of reaction mixture through the side arm into the receiver. This makes a mess. The solutions I found helpful were
using a larger 125 ml flask as the reaction vessel with a longer section of hose fed into the receiver. The hose is connected to a section of 90
degree glass pipe through a one hole stopper. The stopper to the flask is much larger than the test tube stopper and squeezes in tightly with a
greater surface area. It has not fired off into the air like the original set up. As of now reaction batch sizes are increased to around 5 ml H2SO4/AN
with 5 ml H2O and 3 g hydrazine sulfate.
Hoses degrade from the gasses and so they are consumables in this method but very short lengths are used. I should also mention that I leave the area
after the reaction begins and allow it to proceed for 30 min before returning. If I have to stay in the area next to the reactor, I put a stack of
bricks in front of the glass for the unlikely hazard of detonation. For clean up I use paper towels and a waste beaker and put all of the contents
into a hot fire out doors after cleaning. Im still working on optimizing this method but I thought it was pretty basic and simple. The process that is
occurring isnt well understood but its believed to maybe be a breakdown of N2H4 HNO3 into HNO2 that then forms HN3. Using a mixed nitrate salt drain
opener reaction mix along with simple hydrazine sulfate makes this method of azide very simple compared to other methods. Azide can be prepared
quickly because the reaction is only around 15 minutes and the preparation is very minimum as there is no staging. No requirement of nitrite and
hydrazine sulfate can be used direct without free basing.
edit:
I would like to know how other people clean up their equipment after making azides. I would imagine that there are some tips I could pick up because
other than making a nitrite bath and dumping everything in, I'm not sure what the best way to clean up is other than rinsing everything with water and
using paper towels then incinerating everything,.
[Edited on 7-1-2023 by Hey Buddy]
[Edited on 7-1-2023 by Hey Buddy] |
Interesting read. I had the luxury of Sodium azide being available back when I was younger and braver- Glad you've survived learning this process
(so far). Also glad you have had the foresight to barricade the process and retire, this is well into the "WHEN, not IF something will go wrong"
category.
I'm not going to replicate these processes, I'm not brave enough to play with free HN3. You've no doubt read the toxicology information and the
copious historical material on HN3 related accidents? Incidents like a university maintenance worker getting some fingers blown off when disassembling
chemistey lab hood duct work which HN3 had been vented through, various deposits of contaminants in the duct & the rivets fastening the ductwork
together having become coated with primary explosives thereby?
Years ago, I used a bit of amorphous silver azide in some small special effects charges to emulate bullets striking metal surfaces for a video.
Shooting outdoors on a windy, dry, cold fall day, our crew was wearing some wool and synthetic clothing (static electricity generating). One of the
scenes needing to be re shot, my partner reached into the .50 BMG mmo box where a number of these small charges were stored, individually taped to
cards and (we thought) well enough separated to prevent mass explosion. On touching one of these cards, static fired the device and several others in
the container- I re read the literature on ESD sensitivity of primary explosives and quit making/using silver azide.
Be careful and don't get acclimated and blase about personal protection, always proceed on the assumption that such things will explode during
processing/storage- Because if you work with them often enough, eventually, they will.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
|
|
|
Hey Buddy
Hazard to Others
Posts: 429
Registered: 3-11-2020
Location: Bushwhacker Country
Member Is Offline
|
|
Thanks for the words of warning.
I hope that the explosion certainty is not as absolute as you suggest. It is diluted. The first time I tried this I forgot to bung up the receiver
because I was so nervous thinking about HN3. I was basically generating diluted HN3 freely in the air. Oops. I like this method but I think overall it
is a little inefficient. If I can ever cause an explosion using this method I will be sure to come back and report.
[Edited on 8-1-2023 by Hey Buddy]
|
|
|
dave321
Harmless
Posts: 45
Registered: 22-11-2012
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by Bert | | Quote: Originally posted by Hey Buddy | I've been doing sabanejeff-oxidation derived lead azide (dextrin and cmc). I saw this demonstration set up on Astral Chemistry's video channel. This
photo is the first arrangement used. I copied his set up. Sidearm test tube as reaction vessel. HN3 diluted with N2 and NO2 is generated and fed into
a broke off pipette tip through a two hole stopper into lead acetate/cmc/dextrin aqueous solution. The other hole in the stopper has a short section
of pipette connected to a vinyl output hose feeding into a water trap. Hydrazine sulfate and 50% concentration nitric acid are loaded into the
reaction chamber, a gentle heat is applied to the reaction tube, around 30 sec to a min of heating by an electric heat gun initiates the reaction
smoothly. Generating a movement of the reaction mixture and a fizzing followed by bubbling then intense bubbling then tapering off. Mixed HN3 gas is
fed into the receiver chamber loaded with your solution of choice, inorganic hydroxides, acetates and nitrates are the usual solutions.
I have not attempted this with organic substrates. I have been trying this set up using OTC drain cleaner/ AN in situ nitric acid salt mix, instead of
the usual diluted HNO3. It generates HN3 almost as smoothly as using HNO3.
I have had some lessons learned using this set up. Obviously, HN3 is the greatest danger presented by any method using hydrazoic acid, its very
poisonous and explosive when concentrated. This method is advantageous in that its risk of detonation is minimized by small amounts of gas produced at
a time as the reaction proceeds and the gas then neutralized at end point use creating azide directly. The gas is also diluted by the nitric acid
presence which is definitely feeding NO and NO2 and maybe some N2 into the stream.
The gas pressure can become intense depending on the vessel and mass of reactants. Astral recommended 1.5 g N2H6SO4 for 4 cc of 50% HNO3. That ratio
works smoothly. In modifying the procedure to use NO3 salt, I tried at first mixing hydrazine salt with nitrate salt in the reactor and adding H2SO4.
This results in quite an immediate reaction. Ive also blown off the stopper from excess gas pressure from too vigorous of a gas generation, this
should be avoided because it off vents hydrazoic acid into the ambient environmentif you are not using a hood. A better method is to first react the
H2SO4 with nitrate salt for around 15 minutes prior to loading it into the reactor with the hydrazine inside. This method has no immediate reaction
and a reaction doesnt begin until the reactor is heated to around ~100 C.
I have also had issues with bubbling of reaction mixture through the side arm into the receiver. This makes a mess. The solutions I found helpful were
using a larger 125 ml flask as the reaction vessel with a longer section of hose fed into the receiver. The hose is connected to a section of 90
degree glass pipe through a one hole stopper. The stopper to the flask is much larger than the test tube stopper and squeezes in tightly with a
greater surface area. It has not fired off into the air like the original set up. As of now reaction batch sizes are increased to around 5 ml H2SO4/AN
with 5 ml H2O and 3 g hydrazine sulfate.
Hoses degrade from the gasses and so they are consumables in this method but very short lengths are used. I should also mention that I leave the area
after the reaction begins and allow it to proceed for 30 min before returning. If I have to stay in the area next to the reactor, I put a stack of
bricks in front of the glass for the unlikely hazard of detonation. For clean up I use paper towels and a waste beaker and put all of the contents
into a hot fire out doors after cleaning. Im still working on optimizing this method but I thought it was pretty basic and simple. The process that is
occurring isnt well understood but its believed to maybe be a breakdown of N2H4 HNO3 into HNO2 that then forms HN3. Using a mixed nitrate salt drain
opener reaction mix along with simple hydrazine sulfate makes this method of azide very simple compared to other methods. Azide can be prepared
quickly because the reaction is only around 15 minutes and the preparation is very minimum as there is no staging. No requirement of nitrite and
hydrazine sulfate can be used direct without free basing.
edit:
I would like to know how other people clean up their equipment after making azides. I would imagine that there are some tips I could pick up because
other than making a nitrite bath and dumping everything in, I'm not sure what the best way to clean up is other than rinsing everything with water and
using paper towels then incinerating everything,.
[Edited on 7-1-2023 by Hey Buddy]
[Edited on 7-1-2023 by Hey Buddy] |
Interesting read. I had the luxury of Sodium azide being available back when I was younger and braver- Glad you've survived learning this process
(so far). Also glad you have had the foresight to barricade the process and retire, this is well into the "WHEN, not IF something will go wrong"
category.
I'm not going to replicate these processes, I'm not brave enough to play with free HN3. You've no doubt read the toxicology information and the
copious historical material on HN3 related accidents? Incidents like a university maintenance worker getting some fingers blown off when disassembling
chemistey lab hood duct work which HN3 had been vented through, various deposits of contaminants in the duct & the rivets fastening the ductwork
together having become coated with primary explosives thereby?
Years ago, I used a bit of amorphous silver azide in some small special effects charges to emulate bullets striking metal surfaces for a video.
Shooting outdoors on a windy, dry, cold fall day, our crew was wearing some wool and synthetic clothing (static electricity generating). One of the
scenes needing to be re shot, my partner reached into the .50 BMG mmo box where a number of these small charges were stored, individually taped to
cards and (we thought) well enough separated to prevent mass explosion. On touching one of these cards, static fired the device and several others in
the container- I re read the literature on ESD sensitivity of primary explosives and quit making/using silver azide.
Be careful and don't get acclimated and blase about personal protection, always proceed on the assumption that such things will explode during
processing/storage- Because if you work with them often enough, eventually, they will. |
thats an interesting comment on ESD setting off bullet hits made with amorphous silver azide. There is actually a recent patent in germany for the use
of Silver azide in bullet hits.
Maybe the hits you mentioned were not shunted, and as you say the esd clothing generating would not help.
|
|
|
Bert
Super Administrator
Posts: 2821
Registered: 12-3-2004
Member Is Offline
Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
|
|
The hits were all shunted at the time of incident.
(Edit for long winded explanation)
I have seen some studies of incidents and accidents involving electric matches firing from static electricity even though shunted. Shunting is NOT a
magic spell or silver bullet...
Shunting is a fairly effective method of mitigating RF/EMP related ignitions due to induced current flows in firing lines and ematch "leg" wires.
If you allow a very high voltage/tiny current static charge to build up on yourself or a device with an ematch attached? And handle (even shunted)
ematches or their associated wires in such a fashion that a static discharge path includes the active materials of a match head? MOST PARTICULARLY,
THE FIRST FIRE LAYER? Shunting doesn't help you.
In my case, the ematches involved were made with the old lead thiocyanate/chlorate first fire, now largely superseded by newer and less ESD and impact
sensitive first fire mixtures (non chlorate, no heavy metal salts).
The improvised bullet hits were made by dipping finished commercial ematch heads into a slurry of nitrocellulose lacquer, amorphous silver azide and
fine zirconium powder. MY OUTER COATING WAS EVEN MORE ESD SENSITIVE THAN THE FAMOUSLY SENSITIVE OLD TECH FIRST FIRE LAYER.
If anyone is thinking about copying this technique, most PARTICULARLY for ON BODY bullet hit effects? DON'T. Those commercial film industry devices
are very carefully made to not throw any solid bits, such as fragments of the smalk circuit board chip, lumps of solder and bits of copper wire found
at the core of a standard ematch. Those little bits are quite dangerous when thrown at high velocities- If you've seen witness plates placed near a
metal cased blasting cap, you know.
Live and learn. Don't do things fast as a "field expedient" because a director/producer didn't think to ask for pyrotechnic effects a few weeks before
the shoot started... If there isn't time to source well characterized (commercial!) devices, DONT SHOOT THEIR EFFECTS.
Any accident from such a hasty improvisation is on YOU. And while YOU might be willing to take risks PERSONALLY, ethics should forbid exposing
unknowing others to experiments that go kaboom.
[Edited on 1-18-2023 by Bert]
[Edited on 1-18-2023 by Bert]
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
|
|
|
Hey Buddy
Hazard to Others
Posts: 429
Registered: 3-11-2020
Location: Bushwhacker Country
Member Is Offline
|
|
Update: I heated product from attempted Sabanejeff oxidation using the drain cleaner/NH4NO3 into lead acetate solution. No detonation. Not sure. It
works with HNO3 @ 1.3 d. A reaction takes off and sustains upon gentle heating using salt acid mix exactly the same as HNO3, main difference is HNO3
is very clear in color versus tan>Orange>Red>clear with salt/acid. I will try some other metal salts/concentrations/conditions. try to figure
out why product didn't undergo BTFU.
Ca(OCl)2 solution works really well for cleanup.
|
|
|
Raid
Hazard to Everyone
Posts: 202
Registered: 14-11-2022
Location: N/A
Member Is Offline
Mood: School
|
|
is there a synthesis of sodium azide somewhere here? need some for lead azide 
|
|
|
Bert
Super Administrator
Posts: 2821
Registered: 12-3-2004
Member Is Offline
Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
|
|
Yes, there is a sodium azide synthesis somewhere here.
[Edited on 1-17-2023 by Bert]
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
|
|
|
ManyInterests
National Hazard
Posts: 930
Registered: 19-5-2019
Member Is Offline
|
|
https://youtu.be/eQ2qSBhFndY
Enjoy!
|
|
|
dave321
Harmless
Posts: 45
Registered: 22-11-2012
Member Is Offline
Mood: No Mood
|
|
has anyone here prepared silver azide by the costain process .
and if they have, what was the final product like ?
crystalline and free flowing?
|
|
|
DennyDevHE77
Hazard to Others
Posts: 167
Registered: 15-9-2014
Member Is Offline
Mood: No Mood
|
|
Guys, as you know lead azide is made in the presence of water soluble polymers such as dextrin to get properly formed processable crystals. This is
important for industry to make them friable. And as I understand it gives crystals that are not particularly large in size.
But can the solutions simply be poured together at home? Bulkiness is not particularly important, but I am afraid that with this method, along with
the smallest powder, some particularly large crystals may form, and then the whole mixture becomes dangerous. It seems that crystals above 0.5 mm of
lead azide detonate involuntarily.
|
|
|
Microtek
National Hazard
Posts: 869
Registered: 23-9-2002
Member Is Offline
Mood: No Mood
|
|
If you use a similar sort of procedure to the one I wrote about in the ETN/PETN crystallization thread you'll get the required small crystals. So,
rapid stirring throughout the addition.
|
|
|
Sir_Gawain
Hazard to Others
Posts: 420
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Like a pendulum
|
|
Sodium azide recrystallation
Can sodium azide be recrystallized in water or a water/ethanol mixture? I’ve read that it hydrolyses slowly to release hydrogen azide. Would a small
amount of sodium hydroxide help prevent that? I suspect my sodium azide contains some sodium nitrite/nitrate left over from when I made it, as it
burns very fast and throws unburnt powder everywhere. All other homemade samples I’ve seen burned the same as mine, but commercial samples burn very
differently (see Chemicalforce).
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
DennyDevHE77
Hazard to Others
Posts: 167
Registered: 15-9-2014
Member Is Offline
Mood: No Mood
|
|
I found a technique where sodium azide was calmly dissolved in water, evaporated, crystallized on cold, and repeated the cycle many times, then washed
with alcohol. So I think it's safe to dissolve...
|
|
|
Microtek
National Hazard
Posts: 869
Registered: 23-9-2002
Member Is Offline
Mood: No Mood
|
|
HN3 is a weak acid so when NaN3 is dissolved in water, some of the azide ions will be protonated as the equilibrium reasserts itself. Not a lot
though.
|
|
|
Sir_Gawain
Hazard to Others
Posts: 420
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Like a pendulum
|
|
That’s why I suggested adding a small amount of sodium hydroxide; to push the equilibrium to the other side. I’ve noticed a lot of lead azide
syntheses call for a very tiny amount of sodium hydroxide, presumably to reduce the formation of hydrogen azide.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
Sir_Gawain
Hazard to Others
Posts: 420
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Like a pendulum
|
|
Would it be better to dissolve in a minimal amount of hot water, add hot ethanol until it starts precipitating, then chill to precipitate, or
recrystallize from boiling methanol? Wikipedia lists the solubility as 2.5 g/100 mL of methanol at 25*C, and 0.22 g/100mL of ethanol at 0*C.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
Microtek
National Hazard
Posts: 869
Registered: 23-9-2002
Member Is Offline
Mood: No Mood
|
|
I would suggest doing microscale experiments to see what works best. Consider using a mix of solvents such as water and methanol to do the
recrystallization.
|
|
|
MineMan
International Hazard
Posts: 1004
Registered: 29-3-2015
Member Is Offline
Mood: No Mood
|
|
What’s the point of this when we have NAP? Is this the 1950s?
I truly don’t understand 17 pages on this topic. Even the best azide. LA dextrinated can’t come close to comparing in performance or safety.
Why can’t we all just move on??
|
|
|
EF2000
Hazard to Others
Posts: 153
Registered: 10-5-2023
Location: The Steppes
Member Is Offline
Mood: Taste testing the Tonka fuel
|
|
| Quote: Originally posted by MineMan | What’s the point of this when we have NAP? Is this the 1950s?
I truly don’t understand 17 pages on this topic. Even the best azide. LA dextrinated can’t come close to comparing in performance or safety.
Why can’t we all just move on?? |
We have NAP and ANGN, whole subforum can be officially closed. And deleted.
Wroom wroom
"The practice of pouring yourself alcohol from a rocket fuel tank is to be strongly condemned encouraged"
-R-1 User's Guide
|
|
|
Sir_Gawain
Hazard to Others
Posts: 420
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Like a pendulum
|
|
The objective is, as always, to explore the science.
[Edited on 1-11-2024 by Sir_Gawain]
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
MineMan
International Hazard
Posts: 1004
Registered: 29-3-2015
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by EF2000 | | Quote: Originally posted by MineMan | What’s the point of this when we have NAP? Is this the 1950s?
I truly don’t understand 17 pages on this topic. Even the best azide. LA dextrinated can’t come close to comparing in performance or safety.
Why can’t we all just move on?? |
We have NAP and ANGN, whole subforum can be officially closed. And deleted. |
What is ANGN?
|
|
|
Sir_Gawain
Hazard to Others
Posts: 420
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Like a pendulum
|
|
1-amino-3-nitroguanidinium nitrate.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
Nemo_Tenetur
Harmless
Posts: 31
Registered: 13-12-2023
Location: Germany
Member Is Offline
|
|
| Quote: Originally posted by dave321 | has anyone here prepared silver azide by the costain process .
and if they have, what was the final product like ?
crystalline and free flowing? |
Exactly with one year delay I´ve tried today a modified process claimed to produce superior product quality described in this patent:
https://patents.google.com/patent/US20150321922A1/en
I followed example one with half quantity of each reagent (1,51 gram silver nitrate instead 3,02 gram and so on ) and diluted the whole mixture with
a little bit more distilled water to get the magnetic stirrer bar and immersed thermometer completely covered with the reaction mixture.
The precipitation starts after about 30 minutes and the photo was taken after four hours.
I´m not so happy with the consistency (looks like sludge) and the light to medium grey-colored precipitate. It´s my first attempt to synthesize
silver azide, I haven´t seen this substance until yet.
Is a light to medium grey color normal? The reaction vessel was protected from sunlight, only a weak three watt LED bulb was several meters away, the
reagents used were pure (silver nitrate snow white crystal, colorless reaction mixture at the beginning), so I´m a little disappointed.
|
|
|
Sir_Gawain
Hazard to Others
Posts: 420
Registered: 12-10-2022
Location: Due South of Due West
Member Is Offline
Mood: Like a pendulum
|
|
Yeah, the slight grey color is normal. I just made some a few days ago. Be careful; it can detonate in tiny quantities without containment.
“Alchemy is trying to turn things yellow; chemistry is trying to avoid things turning yellow.” -Tom deP.
|
|
|
Nemo_Tenetur
Harmless
Posts: 31
Registered: 13-12-2023
Location: Germany
Member Is Offline
|
|
Thank you for fast reply. I´ve just cooled the reaction mixture down and filtered the batch into two smaller portions.
Judging from the behaviour during this manipulation, my statement "like sludge" was probably a bit too hasty. With gentle manual swirling, I could
easy remove it from the flask and transfer it to the filter paper. Probably the force of the magnetic stirrer bar was simply too weak to keep it in
motion.
But the color is still the question. Not light grey, more a medium grey. Macroscopically, it looks like atomized aluminum (the cheap 0 - 63 micron
spherical shape, I´ve used plenty amounts in the past).
Now the filter papers (washed first with distilled water, then with IPA) must dry completely before I can perform further tests.
|
|
|
| Pages:
1
..
15
16
17
18 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
